Annually resolved coral d18O and Sr/Ca records from southwestern Puerto Rico are used to investigate
Caribbean climate variability between 1751 and 2004 C.E. Mean surface ocean temperatures in this region have
increased steadily by about 2C since the year 1751, with Sr/Ca data indicating 2.1 ± 0.8C and d18O data
indicating 2.7 ± 0.5C. Coral geochemical records from across the tropics demonstrate that regional variability is
important for understanding climate variations at centennial time scales. A strong multidecadal salinity signal in
the oxygen isotope data correlates with observed multidecadal temperature variations in the Northern
Hemisphere. Instrumental wind and precipitation data indicate that the most recent coral isotopic variations are
caused by expansion and contraction of the steep regional salinity gradient, forced by trade wind anomalies
through meridional Ekman transport. The timing of the fluctuations suggests that the multidecadal-scale wind
and surface circulation anomalies might play a role in Atlantic temperature variability and meridional
overturning circulation, but further work is needed to confirm this suggestion.